How can I improve the topology of this object
From one sub-d way of looking at it, you've got 2 curvatures to capture: the one around the hole, and the one around the cylinder. To keep the cylindrical curve even, it should consist of edges parallel to the bend, as evenly spaced as possible.
So one approach, working in the flat, before bending the piece, is to try to capture the curvature of the hole using only cuts into the lines which will be parallel to the bend...

.. also isolating the hole from the bend by making it the result of an inset: puting a rim of faces around its perimeter.
Working under  Mirror and a Subdivision modifiers, you can see the curves you will wind up with.
The rules aren't hard and fast.. you can bend the up-down lines a little, and add edges around the cylinder wherever they help you out.